Although not clear how much of that free time "less" means, I wish to point out that if you're a male (as I'd guess from your nickname), your contribution to the education of your descendants becomes the most useful after kid's childhood. Progressing as teenagers, they need less and less love and start needing more and more guidance and advice. That's the period where maternal inherent love and affection progressively looses its value. As time goes, when facing problems, the teenager would rather receive insight (which is something expected to be had from a father) instead of consolation. That may be your most needed paternal contribution of the entire offspring upbringing.